First Pass Yield or Quality Yield, Wait… What’s the Difference?

Manufacturing-related quality statistics aren’t normally associated with biorepositories, but the world of statistical process improvement tools can be very useful for biobanking. One such case is the difference between two basic statistical metrics — Quality Yield and First Pass Yield. I'd like to shed some light on both metrics starting with their definition, then propose a recommendation of which to use in a biorepository setting, and conclude with a proposed performance target level.

First Pass Yield vs. Quality Yield

Quality Yield (QY), also known as Final Yield (FY)1 represents the acceptable pieces at the very end of a process divided by the original number of pieces fed into the process. In a manufacturing setting, this tells you the overall proportion of acceptable results; if the number of units of acceptable quality at the end of the process is the same as what can be expected given what is fed into the process, then you have achieved a 100% Quality Yield.1